Factor XIII assay test detects or measures the amount of factor XIII in blood. It is used to help detect a deficiency of factor XIII which is involved in blood clotting. You may require factor XIII assay test if you have factor XIII deficiency disease.

Before having blood collected for a factor XIII assay test, tell the person drawing your blood if you are allergic to latex. Tell the doctor if you have a medical condition or are using a medication or supplement that causes excessive bleeding. Also tell the doctor if you have felt nauseated, lightheaded, or have fainted while having blood drawn in the past.

When a blood sample from a vein is needed, a vein in your arm is usually selected. A tourniquet (large rubber strap) may be secured above the vein. The skin over the vein will be cleaned, and a needle will be inserted. You will be asked to hold very still while your blood is collected. Blood will be collected into one or more tubes, and the tourniquet will be removed. When enough blood has been collected, the doctor will take the needle out.

During a blood draw, you may feel mild discomfort at the location where the blood sample is being collected.

During a blood draw, a hematoma (blood-filled bump under the skin) or slight bleeding from the puncture site may occur. After a blood draw, a bruise or infection may occur at the puncture site. The person doing this test may need to perform it more than once. Talk to your doctor if you have any concerns about the risks of a factor XIII assay test.

Results of a factor XIII assay test may vary depending on your age, gender, health history, the method used for the test, and many other factors.